1. Field of the Invention
The present invention relates to an exercise apparatus for providing simulated walking or running motion and, in particular, a simple, compact exercise apparatus for producing a deep stride natural running motion using a combination of pins, linkages and gears.
2. Description of the Related Art
The benefits of regular exercise to improve overall health, fitness and longevity are well documented in the literature. Medical science has consistently demonstrated the improved strength, health, and enjoyment of life which results from physical activity. Aerobic exercises, such as jogging and walking, are particularly popular and medically recommended exercises for conditioning training and improving overall health and cardiovascular efficiency.
However, modern lifestyles often fail to accommodate accessible running or walking areas. In addition, inclimate weather and other environmental and social factors may cause individuals to remain indoors as opposed to engaging in outdoor physical activities.
There are also certain dangers and/or health risks associated with walking, jogging or running on natural outdoor surfaces. For example, medical experience has demonstrated that knee and ankle joints are often strained or injured when joggers run on paved or uneven surfaces or jogging paths which change direction often. Other examples of common injuries resulting from jogging, particularly on uneven terrain, may include foot sores, pulled or strained muscles, strained tendons and cartilage, back injuries, and head injuries, not to mention the risk of physical harm from pedestrian crossing accidents or even criminal activity. Thus, many exercise enthusiasts prefer the safety and convenience of an in-home or commercial exercise machine in order to provide desired exercise without the attendant inconvenience and risk of outdoor exercise.
Presently available indoor exercise devices for commercial or home use come in a wide variety of sizes and configurations. Typical indoor exercise devices may include, for example, stationary bicycles for simulating bicycle pedaling action, simulated stepping machines for simulating or replicating the motion associated with stair stepping exercise, and treadmills for simulating running, jogging, or walking. Other popular exercise devices include ski simulators and a wide variety of weight lifting or resistance training exercise equipment.
Each of these exercise machines has particular advantages and disadvantages for accomplishing a desired fitness goal. For example, treadmills generally permit a user to walk, jog or run on a stationary platform or endless belt. As such, treadmills are particularly well suited for general fitness and endurance training. However, the foot impact associated with walking or running may be undesirable in some cases due to advanced age, pregnancy, or other health conditions. In those cases it may be beneficial for the user to engage in a more low impact or non-impact exercise.
Cycling simulators, ski simulators, and stair simulators are particularly noted for the elimination of impacts affecting the hips, knees, ankles, and feet of a user. However, such exercise machines have a limited range of motion such that certain muscle groups are often not fully exercised to the degree desired by the user. In particular, these machines do not faithfully reproduce what many consider to be the most natural and beneficial exercise motionsxe2x80x94namely, walking and running.
More recently, elliptical foot path exercise devices have been introduced into the market and have become popular for both home and commercial use. These devices provide a broader range of foot motion generally tracing a path approximating an ellipse or modified ellipse. For example, U.S. Pat. No. 5,299,993 to Stearns shows a modified stair stepping exercise machine which incorporates both vertical and horizontal movement using a combination of linkages to guide the foot pedals in an elliptical or ovate path. Habing in U.S. Pat. Nos. 5,299,993 and 5,499,956 provides articulated linkages controlled through cables by motor to move the foot pedals through an open ovate path. Both devices guide the foot pedals using linkages and rollers operating against a linear guide track.
Like Stearns and Habing, most elliptical path exercise machines utilize a linear guide track to produce the desired elliptical path foot motion. There are several disadvantages associated with such linear guide tracks. Guide tracks, by their nature, tend to make noise when in use due to a bearing or wheel riding back and forth along a track. The track is usually open to accommodate linear motion of the bearing and dust, dirt and grime can accumulate in the track causing noise and undue wear and tear. This can result in significant upkeep and repair to maintain such devices in good working order. Also, the open configuration of the track and the need for lubrication of the track and bearing provides for the possibility of inadvertent exposure of the user or other adjacent surface to greasy or oily stains. In carpeted areas, for example, an open lubricated track can result in difficult-to-remove stains in the underlying carpet.
Linear guide tracks also tend to produce a relatively shallow elliptical running path that is less simulative of the desired natural deep running stride. A deeper running stride is preferred because it is more simulative of the natural running motion and also results in more thorough exercise of the legs and musculature of the lower body of the user. For optimal deep stride running simulation, preferably the overall vertical component of the elliptical foot path displacement is between about one-half to two-thirds of the overall horizontal foot path displacement per cycle.
Elliptical exercise machines utilizing guide tracks rely on the reciprocating back-and-forth motion of the guide-track/bearing system to achieve the desired elliptical foot path motion. This back-and-forth motion tends to impart a jerkiness or discontinuity in the velocity or acceleration of the users foot as it moves along the elliptical path. It is unavoidable that the various moving components comprising the guide track and bearing must have a certain mass and, thus, the dynamics and changing velocities and accelerations of the individual components can often impart to the exercise machine an undesirable uneven stride motion or xe2x80x9ckickxe2x80x9d. This can make the device more difficult to use and decrease the smoothness and non-impact gliding ability of the exercise machine. Excessive acceleration of particularly massive linkages can cause undesired torsional or bending strain within associated support and pivot members, increasing wear and the risk of potential catastrophic failure.
Some of these deleterious effects can be attenuated by increasing the size of a flywheel mass associated with the exercise machine. But this adds weight and cost to the machine and often does not eliminate the jerkiness of the guide path mechanism to the extend desired.
Another drawback of many conventional elliptical path exercise machines is the relatively large amount of space occupied by the machine""s xe2x80x9cfoot-print.xe2x80x9d The foot-print is the amount of floor area an exercise machine occupies when properly set up, giving due consideration for any additional clearances required for safe operation of the machine and for ingress and egress of users. Smaller foot-print machines are more desirable for commercial use, such as in gyms, health spas and the like, because of the cost of renting and maintaining commercial floor space.
Notably, many of the prior art elliptical exercise devices utilize foot pedals that are rigidly attached to extended foot linkages. These foot linkages, in turn, are provided in connected relationship between a crank at one end and a guide or reaction roller at the other end. Therefore, in a conventional elliptical exercise machine the longest dimension of the machine""s foot print typically extends well beyond the major axis of the elliptical foot path. This is due to the fact that the axis of the crank as it turns a wheel or other device when considered with the axis of the connection at the end of the crank limits the overall stroke distance to the working diameter of the crank or twice the crank arm length, which forms the major axis of the elliptical path. Also, the bearing or reaction roller is typically required to be situated well rearward of the foot linkage in order to provide the desired amount of vertical displacement in the elliptical path motion.
For example to achieve a sixteen inch length in the major axis of the elliptical footpath of a conventional elliptical path trainer, the crank of the trainer needs to have a longer crank arm length than half the length which would be eight inches. This takes into account the journaling and bearing mountings. From a practical standpoint in order to provide a sixteen inch length of the major axis of the elliptical path, a nine inch long crank must be utilized to provide approximately an eighteen inch diameter circle. In addition, the foot linkage may extend another twenty-four to thirty-six inches rearward beyond the point of attachment to the crank to engage a guide roller. Thus, the total displacement of the crank and linkage required to achieve a sixteen inch running stride could be as long as forty to fifty inches or more. This translates into an undesirably large or elongated foot print relative to the length of the stride path achieved.
Accordingly, it is a principle object and advantage of the present invention to overcome some or all of these limitations by providing an improved elliptical path exercise machine having a deep stride foot path, that is simple and robust in its construction, requires minimal maintenance, provides smooth even exercise motion, and which has a compact foot-print.
In accordance with one embodiment the present invention provides a lower body cardiovascular exercise machine having a pair of laterally spaced apart foot members. The foot members are coupled to a frame which supports the exercise machine. A first and second guide linkage is pivotally connected to the frame. A first and second articulating linkage is pivotally connected to the guide linkages and a pair of crank arms, respectively. The foot members are pivotally connected to the articulating linkages. By this design, the foot members guide the feet of the user along a preferred deep stride running motion.
In accordance with another embodiment the present invention provides a lower body exercise machine, including a frame configured to be supported by a surface, the frame having a first and a second pivot axis defined thereon and a crank rotatable about the first axis and having a crank arm. A guide linkage is provided having a first and a second end. The guide linkage is pivotally connected to the second axis proximate the first end. An articulating linkage is provided having a first and a second end. The first end of the articulating linkage is pivotally connected to the second end of the guide linkage proximate the first end. The second end of the articulating linkage pivotally is connected to the crank arm between the first and second end. A foot member is provided and pivotally connected proximate the second end of the articulating linkage. The size, shape and connection between the various components and linkages is such that each foot member guides the foot of a user along a preferred anatomical deep stride path simulative of natural running motion.
In accordance with another embodiment the present invention provides a lower body exercise machine including a frame configured to be supported by a surface. The frame includes a first and a second pivot axis defined thereon and a first and second crank each rotatable about the first axis and having a crank arm. First and second guide linkages are provided each having a first and a second end. The guide linkages are pivotally connected to the second axis proximate the first end. First and second articulating linkages are provided each having a first and a second end. The first end of each articulating linkage pivotally connects to the second end of each corresponding guide linkage the first end. The second end of each articulating linkage pivotally connects to the crank arms between the first and second end. First and second foot members are provided pivotally connected proximate the second end of each of the articulating linkages. The size, shape and connection between the various components and linkages is such that each foot member guides the foot of a user along a preferred anatomical deep stride path simulative of running motion.
In accordance with another embodiment the present invention provides an exercise apparatus including a frame and a first crank rotatably connected to the frame defining a first axis. A first link is provided rotatably connected to the crank at the first axis and extending from the first axis to define a second axis radially displaced from the first axis. A second link is provided rotatably connected to the first link at the second axis and extending from the second axis to define and third and fourth axis radially displaced from the second axis. A first foot pedal is pivotally connected to the second link at the third axis to support the foot of a user. A resistance means is operatively connected with the crank to provide exercise resistance.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.